Physicians perform many medical procedures using flexible endoscopes inserted through natural body openings in the patient's body. Flexible endoscopes typically have a flexible shaft with an articulating distal end that the physician may control using actuators on the proximal end of the endoscope. Many flexible endoscopes, including gastroscopes and colonoscopes, have integral working channels (also called biopsy channels or accessory channels) that provide access to the tissue of interest with diagnostic and therapeutic devices. The diameter of the working channel may range from 1 to 4 millimeters, depending upon the size and type of endoscope.
The diameter of the working channel limits the types of medical devices that may be used through the endoscope and the size of objects (e.g., blood clots and biopsy samples) that may be removed from the patient's body. In addition, the physician may be limited to using a single device at a time when using a conventional endoscope having only one working channel, sometimes requiring numerous, time-consuming insertions/removals of the device during a procedure. Certain specialized endoscopes are available that have extra large working channels or a pair of working channels. However, such specialized endoscopes may be more expensive, larger in diameter, stiffer and more difficult to intubate than standard endoscopes.
One example of a medical procedure involving the upper gastrointestinal (GI) tract is placement of an enteral feeding tube into the small intestine of a patient. Such a procedure is generally referred to as a percutaneous endoscopic gastrojejunostomy (PEGJ) procedure. In a gastroscope-assisted PEGJ, the physician may insert and remove a gastroscope into the upper GI tract a number of times in order to place the distal end of the feeding tube in the jejunum under visualization of the endoscope and to secure the proximal portion of the feeding tube to the abdominal and gastric walls. These repeated insertions/removals are time-consuming and may result in significant trauma to tissue and post-procedural soreness in the upper GI tract of the patient.
Similar issues may be associated with current intubating procedures in the lower GI tract by way of the anus of the patient. For example, a patient's comfort may be improved by placing a colonic decompression tube into the colon of the patient, thereby releasing gas and other fluids produced by the body. However, current techniques of navigating a flexible tube through the flexures of the colon may be time-consuming, traumatic to tissue and painful to the patient.
Accordingly, there is a need for improved devices and methods that are adapted for use with a flexible endoscope and that provide improved endoscopic access to the tissue of interest with medical devices for numerous medical purposes, including performing diagnostic and therapeutic procedures, supplying fluid nutrients into the gastrointestinal tract, removing diseased tissue and releasing gas.